The diameter of a circle (also known as its circumference) can be found by the formula c=2πr, where r is the radius and π is the constant pi, commonly approximated to 3.14.
To round this to the nearest unit, look at the tenths place.
If this is...
24.5
Circumference of a circle = 2*pi*radius or pi*diameter Circumference = 21.67698931 or 21.7 meters to the nearest tenth
First, you have to know the formula that connects the circumference of a circle to the diameter. You may have been out or asleep that day. Circumference = (pi) x (diameter) Plug the numbers you know into that formula. 23.56 = pi D D = 23.56 / (pi) That's it. We're sure you can handle the division and the rounding. Use 3.14 for (pi).
50.27 yards
to find the raduis of any circle, divde the diameter by 2. in this case, the answer would be 3.50
A circle has a circumference of 110.6 mm. Find its diameter to the nearest tenth.
24.5
A circle with a diameter of 11 inches has an area of 95.03 square inches.
Circumference of a circle = 2*pi*radius or pi*diameter Circumference = 21.67698931 or 21.7 meters to the nearest tenth
37.7 cm
the diameter of the circle is 9cm. Find it’s area to the nearest tenth
First, you have to know the formula that connects the circumference of a circle to the diameter. You may have been out or asleep that day. Circumference = (pi) x (diameter) Plug the numbers you know into that formula. 23.56 = pi D D = 23.56 / (pi) That's it. We're sure you can handle the division and the rounding. Use 3.14 for (pi).
50.27 yards
to find the raduis of any circle, divde the diameter by 2. in this case, the answer would be 3.50
diammeter*pi= 10 divide both side by pi to find the diameter: diameter = 3.183098862 or 3 cm to the nearest cm.
pi*diameter = 16 inches Divide both sides by pi to find the diameter: diameter = 5.092958179 or 5 inches to the nearest inch.
The answer is that I would try to find out what he understands about rounding and then explain the concept of rounding through examples that he can identify with.